The dumbbell-shaped longitudinal slot antennas are employed as a replacement for the round-ended longitudinal slot antennas. Each dumbbell-shaped slot is excited by an iris and a septum that have offsets from the waveguide centerlines. All the slots are also cut along the waveguide centerlines. It is demonstrated that the resonant length of the proposed dumbbell-shaped slot antennas is much smaller than the round-ended longitudinal slot antennas. Hence, the end-to-end spacings between the adjacent radiating slots as well as the end-to-end spacings between the coupling and the radiating slots increased noticeably in comparison with the arrays consist of the round-ended longitudinal slot antennas. This fact indicates that one can neglect the mutual coupling between the neighboring slots that are associated with the exciting higher-order modes at the slot positions. To better demonstrate the effectiveness of the proposed dumbbell-shaped slot antennas, a planar array antenna consists of the proposed dumbbell-shaped slot antennas have been designed, implemented, and tested. The measurement and the simulation results confirm the effectiveness of the proposed slot antennas.

哑铃形纵向缝隙天线用于替代圆端纵向缝隙天线。每个哑铃形槽由偏离波导中心线的虹膜和隔膜激发。所有槽也沿波导中心线切割。结果表明，所提出的哑铃形缝隙天线的谐振长度远小于圆端纵向缝隙天线。因此，与由圆端纵向缝隙天线组成的阵列相比，相邻辐射槽之间的端到端间距以及耦合与辐射槽之间的端到端间距显着增加。这一事实表明，可以忽略与在槽位置处激发的高阶模式相关的相邻槽之间的相互耦合。为了更好地证明所提出的哑铃形缝隙天线的有效性，由所提出的哑铃形缝隙天线组成的平面阵列天线已被设计、实施和测试。测量和仿真结果证实了所提出的缝隙天线的有效性。